Williston, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

154
FXUS63 KBIS 060400
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1000 PM CST Fri Dec 5 2025

.KEY MESSAGES...

- Near daily chances for light snow through the forecast period.

- Medium to high confidence in 1 to 2 inches of snow along and to
  the south and west of the Missouri River tonight through
  Saturday, with locally higher amounts up to 4 inches in
  southwest parts of the state.

- Medium confidence of light accumulating snow over much of
  western and central North Dakota again on Sunday, with
  accumulations to around an inch along and west of the Highway
  83 corridor.

- A more impactful system could bring strong winds along with
  both rain and snow (medium to high chances) across the region
  Monday night through Tuesday night.

- Temperatures drop to below average this weekend, above average
  Monday and Tuesday, then below average temperatures are favored
  again for the second half of next week.

&&

.UPDATE...
Issued at 959 PM CST Fri Dec 5 2025

The forecast for tonight remains mainly on track. Increased the
timing of snow chances north central, otherwise the rest of POPs
tonight looking good based on radar returns to our west and
latest CAMs. No other major edits to the forecast at this time.

UPDATE
Issued at 632 PM CST Fri Dec 5 2025

Northwest flow aloft this evening continues, with a weak
embedded wave moving across the Dakotas. Weak sfc ridge of high
pressure extends across central North Dakota. A few reports of
light snow/flurries ahead of the mid level wave, with a mix of
low/mid level clouds. We remain on track for a swath of light
snow moving through the region later tonight into Saturday, and
only made some slight modifications to POPs with this update.

&&

.DISCUSSION...
Issued at 248 PM CST Fri Dec 5 2025

Currently, low pressure was situated along the lee of the Northern
Rockies with a cold and dry surface high pressure ridge  from
northern/central Saskatchewan into southern Manitoba. For the most
part, it was dry across the southern half of the state, in the north
associated with a weak inverted trough from northwest into east
central ND.

For late this afternoon into early this evening, there may be some
light snow continuing across the north and possibly a bit of
freezing drizzle with the loss of ice aloft, but in general think
this precip will be very light and on the decrease as high pressure
builds south from Canada.

Late this evening and overnight, cyclogenesis occurs in the northern
High Plains with a surface low depicted in the vicinity of eastern
Wyoming by 12Z Saturday. There is general agreement within the
deterministic model suite in synoptic scale forcing propagating
through southwest ND late this evening through Sunday morning. There
is less agreement in the extent of synoptic scale forcing outside of
the southwest portion of the state. There is also disagreement in
the placement of Frontogenetic forcing. The strongest FG forcing is
at 850 mb over the southwest portion of the state. 70H forcing is
generally along or north of the Canadian border. There is consensus
in moderate to steep lapse rates over most of western and central
ND. The NBM developmental guidance shows a medium to high
probability for at least an inch of snow along, south and west of
Lake Sakakawea and the Missouri River, from 00Z Saturday through 00Z
Sunday, with a medium probability for at least 2 inches of snow over
the far southwest. The probability for at least 4 inches is
generally less than 10 percent, but up to near 20 percent over east
central Montana and to near Beach in southwest ND. Thus given the
ensembles and deterministic guidance there looks to be little change
in the thinking from the previous shift. A medium to High
probability for 1-2 inches of snow south and west of the Missouri
River, with a low potential for up to 4 inches should banding
develop.

On Sunday, another impulse tracks southeast east across the forecast
area, along with warm advection ahead of a warm front.
Deterministic guidance seems to have bumped up the probability for
some light accumulating snows over western and central ND on Sunday,
but as of yet, there`s not much. The NBM is showing some medium
probabilities for an inch or more of snow in the southwest on
Sunday, with generally less than 15 percent chance over central ND.
Would not be surprised to see this increase a bit given the strength
of the wave, warm advection and the possibility of some higher snow
ratios over central ND on Sunday. In general though, light snow
accumulations expected with this feature as well.

We get a brief break on Monday before we see another, possibly
stronger wave track southeast across the region late Monday through
Tuesday. We do warm up on Monday and into Tuesday before we cool
back down for the latter half of the work week. There is still a lot
of uncertainty with this system, but it does look to bring a period
of stronger winds, with the potential for some accumulating snow
north and east, and some rain southwest, with the potential for a
wintry mix in between. Stay tuned!

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 632 PM CST Fri Dec 5 2025

Another round of snow tonight through the day Saturday.

Widespread MVFR ceilings remain across western and central ND
early this evening. May see a brief improvement in ceilings this
evening, especially north and east, as a sfc ridge of high
pressure brings some clearing to the area, including for KMOT
and KJMS. Winds diminish this evening and turn east to northeast
ahead of the next system that moves into the area tonight. With
the next system widespread MVFR to IFR ceilings and
visibilities in snow spreading west to east across the forecast
area later this evening through Saturday morning. LIFR
ceilings/vis possible at times southwest and south central in
heavier areas of snow.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

UPDATE...NH
DISCUSSION...TWH
AVIATION...NH